3: Typical examples of normal appearance of the mammillary bodies (a) compared with acute WKS (b) and chronic WKS (c)

	(a) Coronal section of cerebral hemispheres, showing normal appearance of the mammillary bodies (arrows).
	(b) Coronal section of cerebral hemispheres in a case of acute Wernicke's encephalopathy, showing brownish discoloration (necrosis) of the tissues in the walls of the third ventricle (arrows) and in the mammillary bodies. Some but not all cases of acute Wernicke's encephalopathy have petechial haemorrhages in the same distribution as the necrosis.
	(c) Coronal section of cerebral hemispheres, showing shrinkage and brownish discoloration of the mammillary bodies which is characteristic of chronic Wernicke's encephalopathy. There is dilatation of the third and lateral ventricles consistent with cerebral atrophy, a common finding in this disorder.